Electronic still store with high speed sorting and method of operation

ABSTRACT

An electronic still store system stores and selectively outputs video image data defining a plurality of signal frame still images. The simultaneous display of up to 16 or more quarter sized images for scanning or sorting by an operator is facilitated by generating a quarter sized copy of each newly received image frame and storing both together on a conventional magnetic disk storage device as is typically employed in general purpose digital computing systems. The quarter sized image can then be recalled directly for a multi-image scan or sort function in which 16 reduced size images are displayed simultaneously without the time delays associated with the retrieval and size reduction of 16 full size images.

This is a continuation of application Ser. No. 740,297, filed on May 31,1985, now abandoned, which is a continuation of application Ser. No.483,327, filed Apr. 8, 1983, now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to a digital electronic still store for broadcasttelevision signals and more particularly to a still store providing ahigh speed multiimage scan or sort capability.

Digital electronic still store video display systems store a pluralityof frames of video images on relatively low cost magnetic disk storage.Any selected one of the stored image frames may then be communicated toa frame store from which data defining the image is repetitively readout to generate a continuously displayed television image. The stillstore image can then be combined with a second image to create acombined video image. For example, it is common to insert a selectedstill store image depicting a news event in the upper left hand cornerof a live studio image depicting a newscaster describing the news event.

The disk store is capable of storing a large library of single frameimages and it is often desirable to generate a reduced size multipleimage picture for editing or other purposes. For example, it might bedesirable to create a special effect with multiple images or an editormay wish to view and compare several images at the same time for thepurpose of selecting those images which will be used in a televisionbroadcast. However, each of the several images which are to besimultaneously displayed must first be read from the disk store as fullsize images and then reduced for insertion into the multi-image display.This process takes 1/4 to 1/2 second for each image and results in adelay of several seconds for the composite multi-image display. Such atime delay is at best disconcerting for a busy editor and precludes useof the editing features of the system during a real time broadcast.

U.S. Pat. No. 4,172,264, "Control Arrangement for Video Synchronizers",to Taylor et al describes an arrangement in which joysticks may be usedto selectively position video images on a television display. The systemrequires full sized images to be accessed and then reduced in size asdescribed above.

U.S. Pat. No. 4,302,776, "Digital Still Picture Storage System With SizeChange Facility", to Taylor et al discloses a still store system inwhich multiple images may be accessed and reduced in size forsimultaneous display as discussed above. The suggestion is made that anarray of reduced size images be stored as a single image frame. This hasthe effect of eliminating the time required to reproduce the array butprecludes the flexibility of choosing or repositioning any desiredimages when recalling the array. Furthermore, the aforementioned timedelays are encountered when assembling the original multi-image display.

SUMMARY OF THE INVENTION

An electronic still store system in accordance with the inventionrapidly generates and outputs for display to an operator a still imageframe comprising a plurality of selectively positioned, reduce sizeimages which may be simultaneously viewed for scanning or editingpurposes. The system includes an image store for storing therein aplurality of frames of video images with both a full spatial resolutioncopy for full size video output and a reduced spatial resolution copyfor reduced size video output of each image being stored, and a framestore which is operable in a first mode to receive from the image store,store and repetitively generate a full spatial resolution output imageframe. The frame store is operable in a second mode to receive from theimage store and store a plurality of reduced spatial resolution imageframes. The frame store is further operable in the second mode torepetitively generate an output image frame having an image from each ofthe plurality of reduced spatial resolution image frames selectivelylocated at a different position within the output image frame.

The system may further include an image size reducer coupled to producea quarter size reduced spatial resolution image in response to a fullresolution image stored by the frame store, a video input, ananalog-to-digital converter coupling the video input to the frame store,a monitor for viewing output video images and an outputdigital-to-analog converter coupled to convert the output video imagesfrom a digital form to an analog form for use by the monitor. A centralprocessing unit is connected to receive user commands through a userconsole and to control the other devices of the system in responsethereto.

The image store employed herein is a general purpose magnetic diskstorage system as is currently used in general purpose digital computersystems.

In operation the system can rapidly assemble an array of 16 reduced sizeimages for output as a single image frame. A system operator may viewthe reduced size images simultaneously for rapid scanning of some or allof the stored images within the image store, which is preferably amagnetic disk. Because the images are read from the image store inreduced size and spatial resolution, the output image formation time isapproximately the 1/4 to 1/2 second required to transfer a single fullsize image instead of the several seconds which would be required totransfer 16 full size images prior to resolution reduction and storageas a reduced size image.

Using this system an operator may rapidly scan many still frame imageswhich are stored by the image store or may compile lists of randomlyselected image frames for simultaneous viewing as an array of reducedsize images. Because of the rapid response rate the system becomesfeasible for development and outputting of data frames containingmultiple reduced size images on demand during a television broadcast.

BRIEF DESCRIPTION OF THE DRAWING

A better understanding of the invention may be had from a considerationof the following detailed description taken in conjunction with theaccompanying drawing in which the sole FIGURE is a block diagramrepresentation of an electronic still store system in accordance withthe invention.

DETAILED DESCRIPTION

Referring now to the sole FIGURE, a digital electronic still storesystem 10 for rapidly assembling as a single image frame an array ofreduced size images is shown as including a video input circuit 12. Thevideo input circuit 12 may be another electronic still store system, aTV camera, or some other source of video data from which one or moreframes of a video image may be captured. In the preferred embodiment ofthe electronic still store system 10, the video signal is processed incomponent form. A method and apparatus for producing the componentinformation which may be employed is more fully disclosed in the U.S.Pat. No. 4,675,876, issued Sept. 22, 1987 to D. Beaulier, which isassigned to the same assignee as this application, which is incorporatedby reference herein. Therefore, the video input 12 will includeappropriate video signal decoding means to process video data receivedfrom sources that provide the data in an encoded form.

An input analog-to-digital (A-D) converter 14 is coupled to receive aninput video signal provided by the video input circuit 12, whichtypically includes video signal processing circuitry that prepares thesignal for conversion by the A-D converter 14. The A-D converter 14converts the input video signal to a digital form which is suitable forhandling and processing by digital circuitry. The input AD 14 receivesthe video signal from the video input 12 and converts the video signalto the digital sampled data form in which each pixel of video data isrepresented by three eight bit data bytes defining respectivelyluminance, red chrominance and blue chrominance components.Conventionally, the chrominance data has half the spatial resolution ofthe luminance data in the horizontal dimension so that data is producedin a repetitive 4 byte luminance/chrominance component sequence of L1,CR1, CB1, L2--L3, CR3, CB3, L4 and so forth. The single byterepresentation affords a high dynamic resolution of 256 distinguishablestates for each color component. For adequate dynamic resolution, eachvideo component at a sampled data point is preferably defined by atleast 6 binary bits providing 64 distinguishable intensities. A centralprocessing unit (CPU) 16 formed from a Z80 microprocessor is connectedto receive operator commands from a user console 18. CPU 16 is connectedfor bidirection communication of commands and other data over a systembus 20. The system bus 20 is connected to input A-D 14 as well as othermajor components of the still store system 10 to carry the address, modeselect and status information required to control the operation of thestill store system 10.

A frame store 22 which in the preferred embodiment is a random accessmemory, is coupled to receive mode control information from CPU 16 oversystem bus 20 and to receive video data representing a frame of a videoimage from either input A-D 14 or from a multiple frame image storeimplemented as a magnetic disk drive store 24 in the preferredembodiment but which can be any bulk storage memory device in otherembodiments. Frame store 22 is a random access store that is capable ofstoring more data than is required for a single video image frame.

The storage capacity provided by presently available 64K memory chipsenables storing up to 750 lines of video data. In any event, out of a525 line NTSC frame of data only about 484 lines represent video data.Because of the two dimensional nature of a video image a quarter sizeimage defined by video data having one-fourth the spatial resolution ofa full size image requires one-sixteenth the storage capacity of a fullsize, full spatial resolution image. A quarter resolution image thusrequires the equivalent storage of 30 lines of a full resolution image.In any event the frame store 22 either contains initially or is expandedto contain, storage of video data representing a full resolution fullsize image, as well as a quarter resolution copy thereof.

A size reducer 26 is connected to be controlled by data from CPU 16received over the system bus 20. Size reducer 26 is operable to receivevideo data from frame store 22 to convert the video data to a quarterspatial resolution copy thereof, and communicate the quarter resolutioncopy back to frame store 22 for storage therein. In a similar fashion,when video data received from disk store 24 does not contain acorresponding quarter spatial resolution copy, size reducer 26 may beemployed to generate a quarter spatial resolution copy for subsequenttransfer to either frame store 22 or disk store 24. Hence, any timeframe store 22 receives a video image frame that does not have acorresponding quarter resolution copy, the size reducer 26 may be usedto make such a copy.

As a new frame of video data is transferred from frame store 22 to diskstore 24 for more permanent storage, both the full resolution and thequarter resolution copy are transferred. Since the quarter resolutioncopy is represented by only one-sixteenth the data of a full resolutioncopy, the communication and storage of the quarter resolution copyimposes only a small burden on both system operating time and extrastorage space requirement within disk store 24. It should be noted thatdisk store 24 is a general purpose magnetic disk storage device as iscommonly used in connection with general purpose digital computingsystems.

During system 10 operation frame store 22 repetitively accesses storedvideo data to generate a continuous stream of output video data framesrepresenting the stored image. An output digital-to-analog converter 28receives this digital output data and converts it to an analog videosignal which is subsequently supplied to output processor 32. Outputprocessor 32 is a conventional video signal output processor, forforming a television signal in a standard format, which can be used todrive a monitor 30 for viewing of the output video image by a systemmonitor. The analog video signal form may also be communicated to studioequipment for further use, broadcasting or storage.

When operating in a first, normal broadcast mode, frame store 22receives a full resolution frame of video data from disk store 24 andoutputs a continuous television image in digital data form in responsethereto.

In a second, editing or browsing mode, CPU 16 commands disk store 24 tooutput reduced resolution image data which is selectively positioned inframe store 22 for viewing in one of 16 reduced size image positions ina 4×4 array as a mosaic which fits within a normal full size image.Under operator control, the 16 viewable images may be taken sequentiallyfrom disk store 24 starting with a selected image frame. This mode isuseful when scanning all of the images stored by disk store 24.Alternatively, the 16 images may be taken randomly from a list of storedimages developed by the operator. This mode is especially useful when itis desired to compare certain images.

The 16 image assembly time is greatly reduced because only an amount ofdata equivalent to one full size, full spatial resolution, image need betransferred from disk store 24 to define all 16 images. This is onlyone-sixteenth of the time that would conventionally be required.

While there has been shown and described above, a particular arrangementof an electronic still store system which can rapidly compose a multipleimage frame of data, for the purpose of enabling a person skilled in theart to make and use the invention, it will be appreciated that theinvention is not limited thereto. Accordingly, any modifications,variations or equivalent arrangements within the scope of the attachedclaims should be considered to be within the scope of the invention.

What is claimed is:
 1. An electronic still store system comprising:animage store means for retrievably storing therein a plurality of imageframe copies of video frames, the image frame copies comprising datarepresenting full spatial resolution images and corresponding datarepresenting reduced spatial resolution images of the video frames;frame store means for receiving and storing in a first mode one of saidfull spatial resolution images from said image store means and forrepetitively generating a full spatial resolution image output, and in asecond mode for receiving from the image store means and storing aplurality of said reduced spatial resolution images each at selectivelylocated different positions, the frame store means in the second modefurther repetitively generating an image output comprising the storedplurality of said reduced spatial resolution images; and size reducermeans for receiving from the frame store means the stored full spatialresolution image and in response thereto returning to the frame storemeans a corresponding reduced spatial resolution image, wherein theframe store means receives and stores the returned reduced spatialresolution image while continuing to store the stored full spatialresolution image.
 2. The electronic still store system according toclaim 1, wherein the reduced spatial resolution images each have aspatial resolution of one-fourth the spatial resolution of thecorresponding full spatial resolution image.
 3. The electronic stillstore system according to claim 1, wherein said frame store meansincludes a central processing unit, controlled by an operator in saidfirst mode for selecting which of said full spatial resolution imagesstored in said image store means is to be retrieved from the image storemeans, and in said second mode for selecting which of said reducedspatial resolution images stored in said image store means are to beretrieved and stored in said frame store means, and further forselecting the different positions within a video frame at which each ofsaid retrieved reduced spatial resolution images is stored.
 4. Theelectronic still store system according to claim 3, wherein said framestore means further comprises an output digital-to-analog convertercoupled to receive output image data from the frame store means and inresponse thereto to generate an analog video signal representing anoutput image; anda monitor coupled to receive the analog video signaland display the output image represented thereby.
 5. The electronicstill store system according to claim 4, further comprising a videoinput means for generating an input analog video signal representing aninput video image and an analog-to-digital converter coupled between thevideo input means and the frame store means for converting the inputanalog video signal to a digital form such that digital datarepresenting said input video image is received and stored by the framestore means.
 6. A video still store system comprising:external sourcemeans for supplying a full size image data set representing a full sizeimage frame; a size reducer coupled to receive the full size image dataset for producing therefrom a reduced size image data set representing acorresponding reduced size image frame: an image store for storing aplurality of full size image data sets representing a plurality of fullsize image frames and for storing a plurality of reduced size image datasets representing a plurality of reduced size image frames, each of saidreduced size image data sets corresponding to one of said full sizeimage data sets; and frame store means for storing one of said full sizeimage data sets from either the external source or said image store,wherein if said image store does not supply a corresponding reduced sizeimage data set, said frame store outputs a copy of said full size imagedata set to said size reducer, and receives in turn a correspondingreduced size image data set; wherein said image store stores the reducedsize image data set along with the previously stored corresponding fullsize image data set.
 7. An apparatus for storing video pixel datarepresenting video images of a first resolution and, for each each ofthe images at said first resolution, a corresponding video image at asecond resolution, comprising:random access memory means for storingvideo pixel data representing one of a succession of full size images atsaid first resolution and a corresponding reduced size version thereofat said second resolution; bulk memory means for receiving said videopixel data from said random access memory means and for storing saidsuccession of full size images and the corresponding reduced sizeversions thereof, and for outputting upon a user's command, either aselected one of the successive full size images or selected ones of thecorresponding reduced size versions thereof for direct transfer to, andstorage back in, said random access memory means; and means responsiveto said random access memory means for selectively generating one ofsaid corresponding reduced size versions from the respective full sizeimage in said random access memory means, and for transferring the videopixel data representing and the corresponding reduced size version backto the contents of said random access memory means.
 8. An apparatus forstoring video pixel data as at least one full size image at a firstresolution, and at least one reduced size image thereof at a secondlower resolution, comprising:random access memory means having an inputport and an output port, for storing the video pixel data presented atthe input port; said video pixel data representing the full size videoimage at a first resolution being stored in a first group of memorylocations in said random access memory means; bulk storage memory foralso storing the video pixel data and for presenting selected groups ofvideo data at said input port for storage by said random access memorymeans; size reducing means responsive to said random access memory meansfor directly receiving said video pixel data stored in said randomaccess memory means representing said full size image at said firstresolution, and for reducing said image to the reduced size image at thesecond lower resolution, and for supplying said reduced size image atsaid second resolution directly back to said random access memory meansin a second group of memory locations therein; control means coupled tosaid random access memory means, to said bulk storage memory and to saidsize reducing means, for causing said size reducing means to generatesaid reduced size image at said second resolution and to supply same tosaid random access memory means in said second group of memorylocations; and said control means further causing the transfer of thefull size and reduced size video pixel data from said random accessmemory means to said bulk storage memory for storage, and for causingthe selective transfer from said bulk storage memory directly into saidrandom access memory means of either said full size image at said firstresolution or said reduced size image at said second lower resolution.9. The apparatus of claim 8 wherein said size reducing means producessaid reduced size image at said second resolution with one fourth thespatial resolution of said full size image at said first resolution, andwherein said control means determines the transfer of said reduced sizeimage at said second resolution into said random access memory means forstorage at a selected one of 16 predetermined groups of said memorylocations.
 10. A system for storing video data representing video imageswhich are displayable as rasters of vertically distributed horizontallines, each represented video image normally occupying a raster ofselected vertical and horizontal size, the system comprising:a videoimage size reducer having an input for receiving video data representinga video image corresponding to the selected raster size and forgenerating video data representing a reproduction of said video image ata selected fractional-size of said selected raster size; a first storefor receiving video data for storage and for providing video datatherefrom, said first store having a capacity for storing the video datarepresenting the video image corresponding to the selected raster sizesimultaneously together with the video data supplied by said video imagesize reducer representing said reproduction of the video image at theselected fractional-size; a second store for receiving and storing thevideo data stored in the first store and for providing video datatherefrom directly to the first store, said second store further storingvideo data representing a plurality of additional video images eachcorresponding to the selected raster size, and video data representing aplurality of additional reproductions at the selected fractional size ofsaid selected raster size; and means for selectively transferring fromsaid second store directly to said first store either video datarepresenting of the plurality of video images corresponding to theselected raster size, or video data representing a plurality ofreproductions at the selected fractional-size of said selected rastersize.
 11. A method of storing video pixel data comprising:receiving andstoring in selected storage locations in a random access memory, fullvideo pixel data comprising a full size image; generating from the fullvideo pixel data, reduced video pixel data representing a reproductionthereof in the form of a reduced size image at a lower resolution;storing the reduced video pixel data representing the reduced size imagein additional storage locations in said random access memory along withthe full video pixel data; storing both the full size image and thereduced size image in bulk storage memory; and selectively transferringeither the full size image or the reduced size image from said bulkstorage memory into said random access memory for further processing.12. A video still store system comprising:an external source forsupplying a plurality of full size image data sets representative ofcorresponding full size images; an image store for storing said fullsize image data sets, and for storing a like plurality of reduced sizeimage data sets representing a plurality of reduced size images, each ofsaid reduced size image data sets corresponding to one of the full sizeimage data sets; a memory for simultaneous storage of one of said fullsize image data sets and a corresponding one of said reduced size imagedata sets; a size reducer means for receiving from said memory thestored one of said full size image data sets, and for producing andreturning to said memory the corresponding one of said reduced sizeimage data sets; said memory being responsive to either the externalsource or the image store for storing said one of said full size imagedata sets, and for supplying to the image store both the stored one ofsaid full size image data sets and the corresponding one of said reducedsize image data sets; said memory being responsive to the image store tostore at different selected locations the plurality of reduced sizeimage data sets; said memory further supplying as an output image eitherthe plurality of reduced size image data sets arranged at differentlocations within the output image, or the full size image data set; andmeans responsive to said memory for displaying the output image as araster scanned video display.
 13. A method of storing video pixel datafor access and display comprising:providing data sets for a plurality offull size images at a first spatial resolution; generating, from thedata sets of the full size images, second data sets representing acorresponding plurality of reduced size reproduction images at a secondlower spatial resolution; storing both the data sets of the plurality offull size images and the data sets of the corresponding plurality ofreduced size reproduction images in respective selected groups ofstorage location; and selectively accessing from the storage locations adata, set representing one of the plurality of full size images, and adata set representing one of the corresponding plurality of the reducedsize reproduction images, simultaneously.
 14. An apparatus for storingvideo pixel data as at least one full size image at a first resolution,and at least one reduced size image thereof at a second lowerresolution, comprising:random access memory means having an input portand an output port, for storing the video pixel data presented at theinput port; said video pixel data representing the full size video imageat a first resolution being stored in a first group of memory locationsin said random access memory means; bulk storage memory for also storingthe video pixel data and for presenting selected groups of video data atsaid input port for storage by said random access memory means; sizereducing means responsive to said random access memory means forreceiving said video pixel data stored in said random access memorymeans representing said full size image at said first resolution, andfor producing reduced size pixel data representing the reduced sizeimage at the second lower resolution, and for supplying said reducedsize image at said second resolution to said random access memory meansin a second group of memory locations therein; control means coupled tosaid random access memory means, to said bulk storage memory and to saidsize reducing means, for causing said size reducing means to generatesaid reduced size image at said second resolution and to supply saidreduced image to said random access memory means in said second group ofmemory locations; said control means further causing the transfer of thefull size and reduced size video pixel data from said random accessmemory means to said bulk storage memory for storage, and for causingthe selective transfer from said bulk storage memory into said randomaccess memory means of either said full size image at said firstresolution or said reduced size image at said second lower resolution;and wherein said control means also determines the selective transfer ofsaid reduced size image at said second resolution from said sizereducing means into said bulk storage memory via the random accessmemory means.
 15. A method of storing video pixel data for access anddisplay comprising:providing data sets for a plurality of full sizeimage at a first spatial resolution, wherein each one of the full sizeimages occupies upon display a raster of selected vertical andhorizontal size; generating, from the data sets of the full sizeimages,second data sets representing a corresponding plurality ofreduced size reproduction images at a second lower spatial resolution;storing both the data sets of the plurality of full size images and thedata sets of the corresponding plurality of reduced size reproductionimages in respective selected groups of storage locations; selectivelyaccessing from the storage locations a data set of one of the pluralityof full size images, and one of the sets of the corresponding pluralityof the reduced size reproduction images simultaneously; wherein the stepof accessing further includes, retrieving a plurality of reproductionimages, storing the retrieved plurality of images in a random accessmemory, and outputting the stored plurality of retrieved images as amosaic of reproduction images occupying a raster of the selectedvertical and horizontal size.